U.S. patent number 8,636,125 [Application Number 12/855,820] was granted by the patent office on 2014-01-28 for actuation device having wiper seals for a dual clutch transmission.
This patent grant is currently assigned to GM Global Technology Operations LLC. The grantee listed for this patent is Edward J. Billings, John A. Diemer, Joakim Hogberg, Robert Neil Paciotti, James M. Partyka. Invention is credited to Edward J. Billings, John A. Diemer, Joakim Hogberg, Robert Neil Paciotti, James M. Partyka.
United States Patent |
8,636,125 |
Diemer , et al. |
January 28, 2014 |
Actuation device having wiper seals for a dual clutch
transmission
Abstract
A dual clutch actuation device generates the axial compression
force required to compress a first and second set of frictional
elements of a dual clutch module. Dual clutch actuation device
includes a first and second annular piston. The annular pistons are
arranged in concentric annular piston slots. Together the piston
and annular slots form annular piston chambers. The actuation
device further includes a first set of wiper seals and a second set
of wiper seals disposed in a first and a second annular channel in
each of the annular pistons. Advantageously, contamination of the
piston chambers is reduced or eliminated through the wiping or
cleansing action of the first and second set of wiper seals against
walls of the annular slots formed in the housing of the actuation
device.
Inventors: |
Diemer; John A. (Farmington
Hills, MI), Billings; Edward J. (Ann Arbor, MI), Hogberg;
Joakim (Vanersborg, SE), Partyka; James M.
(Clarkston, MI), Paciotti; Robert Neil (White Lake, MI) |
Applicant: |
Name |
City |
State |
Country |
Type |
Diemer; John A.
Billings; Edward J.
Hogberg; Joakim
Partyka; James M.
Paciotti; Robert Neil |
Farmington Hills
Ann Arbor
Vanersborg
Clarkston
White Lake |
MI
MI
N/A
MI
MI |
US
US
SE
US
US |
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|
Assignee: |
GM Global Technology Operations
LLC (Detroit, MI)
|
Family
ID: |
43623211 |
Appl.
No.: |
12/855,820 |
Filed: |
August 13, 2010 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20110048887 A1 |
Mar 3, 2011 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61237096 |
Aug 26, 2009 |
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Current U.S.
Class: |
192/48.607;
192/85.54; 192/30W |
Current CPC
Class: |
F16D
25/10 (20130101); F16C 19/54 (20130101); F16D
21/06 (20130101); F16D 25/083 (20130101); F16D
25/087 (20130101); F16C 19/163 (20130101); F16D
2021/0615 (20130101); F16C 2361/43 (20130101); F16D
2021/0669 (20130101) |
Current International
Class: |
F16D
25/08 (20060101); F16D 21/00 (20060101); F16D
25/10 (20060101) |
Field of
Search: |
;192/48.607,30W |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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602004001215 |
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Mar 2007 |
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DE |
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602004009042 |
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Jun 2008 |
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DE |
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0185176 |
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Jun 1986 |
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EP |
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0185176 |
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Aug 1986 |
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EP |
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Other References
Machine Translation of EP0185176. cited by examiner.
|
Primary Examiner: Le; David D
Assistant Examiner: Hansen; Colby M
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application
No. 61/237,096, filed on Aug. 26, 2009, which is hereby
incorporated in its entirety herein by reference.
Claims
The invention claimed is:
1. A dual clutch actuation device for actuating a dual clutch in a
dual clutch transmission, the dual clutch actuation device
comprising: a housing fixedly secured to the dual clutch
transmission and defining first and second annular slots; a first
annular piston at least partially slidably disposed in the first
annular slot, the first annular piston including an axially facing
first end, a second end opposite the first end, an outer surface
having a first channel, an inner surface having a second channel,
and a first annular end seal fixedly secured to the first end of
the first annular piston, and wherein the first channel is disposed
axially offset from the second channel; a second annular piston at
least partially slidably disposed in the second annular slot, the
second annular piston including an axially facing first end, a
second end opposite the first end, an outer surface having a third
channel and an inner surface having a fourth channel, and a second
annular end seal fixedly secured to the first end of the second
annular piston, and wherein the third channel is disposed axially
offset from the fourth channel; a first annular piston chamber
defined by the first annular slot and the first annular piston,
wherein the first annular piston chamber is filled with a hydraulic
fluid; a second annular piston chamber defined by the second
annular slot and the second annular piston, wherein the second
annular piston chamber is filled with the hydraulic fluid; a first
outer seal disposed in the first channel of the first annular
piston; a second outer seal disposed in the third channel of second
annular piston; a first inner seal disposed in the second channel
of the first annular piston; a second inner seal disposed in the
fourth channel of second annular piston; a first annular bearing
assembly having a first race in contact with the second end of the
first annular piston and a second race in communication with one of
the clutches of the dual clutch; and a second annular bearing
assembly having a first race in contact with the second end of the
second annular piston and a second race in communication with the
other of the clutches of the dual clutch, and wherein the dual
clutch is actuated by independently pressurizing the hydraulic
fluid in at least one of the first and second annular piston
chambers forcing at least one of the first and second annular
pistons to slide out of the first and second annular slots and
wherein the first inner seal and first outer seal prevent debris
from entering the first piston chamber and the second inner seal
and second outer seal prevent debris from entering the second
piston chamber.
2. The dual clutch actuation device of claim 1, wherein the first
and second outer seal further comprises a body portion
substantially disposed in the channels of the first and second
annular pistons and a wiper portion substantially protruding from
the channels of the first and second annular pistons.
3. The dual clutch actuation device of claim 2, wherein the first
and second inner seal further comprises a body portion
substantially disposed in the channels of the first and second
annular pistons and a wiper portion substantially protruding from
the channels of the first and second annular pistons.
4. The dual clutch actuation device of claim 1, wherein the housing
has a central bore concentric with the first and second annular
slots and inward of the first annular slot.
5. The dual clutch actuation device of claim 1, further comprising
a position sensor attached to the housing of the actuation device
for sensing the position of the first and the second annular
pistons.
6. The dual clutch actuation device of claim 5, wherein the
position sensor includes two sensing elements, one for sensing the
position of the first annular piston and the other for sensing the
position of the second annular piston.
7. The dual clutch actuation device of claim 6, wherein one of the
two sensing elements for sensing the position of the first annular
piston is disposed radially outward of the first annular
chamber.
8. The dual clutch actuation device of claim 7, wherein the other
of the two sensing elements for sensing the position of the second
annular piston is disposed between of the first and the second
annular chambers.
9. The dual clutch actuation device of claim 1, wherein the second
annular slot is concentric with and radially inward of the first
annular slot.
10. A dual clutch actuation device for actuating a dual clutch in a
dual clutch transmission, wherein each clutch of the dual clutch
includes frictional members and actuation levers and wherein the
actuation levers apply an axial compression force on the frictional
members to actuate each clutch of the dual clutch, the dual clutch
actuation device comprising: a housing fixedly secured to the dual
clutch transmission and defining first and second annular slots,
wherein the second annular slot is concentric with and radially
inward of the first annular slot; a first annular piston at least
partially slidably disposed in the first annular slot, wherein the
first annular piston has an axially facing first and second end, an
outer surface having a first channel and an inner surface having a
second channel, and wherein the first channel is disposed axially
offset from the second channel; a second annular piston at least
partially slidably disposed in the first annular slot, wherein the
second annular piston has an axially facing first and second end,
an outer surface having a third channel and an inner surface having
a fourth channel, and wherein the third channel is disposed axially
offset from the fourth channel; a first outer seal having a body
portion substantially disposed in the first channel of the first
annular piston and having a wiper portion disposed substantially
outside of the first channel; a second outer seal having a body
portion substantially disposed in the third channel of second
annular piston and having a wiper portion disposed substantially
outside of the third channel; a first inner seal having a body
portion substantially disposed in the second channel of the first
annular piston and having a wiper portion disposed substantially
outside of the second channel; a second inner seal having a body
portion substantially disposed in the fourth channel of second
annular piston and having a wiper portion disposed substantially
outside of the fourth channel; a first annular piston chamber
defined by the first annular slot and the first annular piston,
wherein the first annular piston chamber is filled with a hydraulic
fluid; a first annular seal fixedly secured to the first end of the
first annular piston for sealing the first annular piston chamber;
a second annular piston chamber defined by the second annular slot
and the second annular piston, wherein the second annular piston
chamber is filled with the hydraulic fluid; a second annular seal
fixedly secured to the first end of the second annular piston for
sealing the second annular piston chamber; a first annular bearing
assembly having a first race in contact with the first annular
piston and a second race in communication with one of the actuation
levers of one of the clutches of the dual clutch; and a second
annular bearing assembly having a first race in contact with the
second annular piston and a second race in communication with the
other of the actuation levers of the other of the clutches of the
dual clutch, and wherein the dual clutch is actuated by
independently pressurizing the hydraulic fluid in the first and
second annular piston chambers forcing the first and second annular
pistons to slide out of the first and second annular slots and
apply a force on at least one of the actuation levers and wherein
the wiper portion of first inner seal and first outer seal prevent
debris from entering the first piston chamber and the wiper portion
of the second inner seal and second outer seal prevent debris from
entering the second piston chamber.
11. The dual clutch actuation device of claim 10, wherein the
housing has a central bore concentric with the first and second
annular slots and inward of the first annular slot.
12. The dual clutch actuation device of claim 11, further
comprising a position sensor attached to the housing of the
actuation device for sensing the position of the first and the
second annular pistons.
13. The dual clutch actuation device of claim 12, wherein the
position sensor includes two sensing elements, one for sensing the
position of the first annular piston and the other for sensing the
position of the second annular piston.
14. The dual clutch actuation device of claim 13, wherein one of
the two sensing elements for sensing the position of the first
annular piston is disposed radially outward of the first annular
chamber.
15. The dual clutch actuation device of claim 13, wherein the other
of the two sensing elements for sensing the position of the second
annular piston is disposed between of the first and the second
annular chambers.
Description
TECHNICAL FIELD
The present disclosure relates to transmissions and more
particularly to a dual clutch actuation device for a compact, dual
clutch multiple speed transmission.
BACKGROUND
The statements in this section merely provide background
information related to the present disclosure and may or may not
constitute prior art.
A typical dual input multiple speed transmission has a first input
shaft and a second input shaft that is a hollow sleeve shaft that
is concentric with the first input shaft. The first and second
input shafts are selectively coupled to the engine crankshaft
through a dual clutch. The dual or twin clutch has two independent
clutch units that are each separately rotationally fixed to one of
the input shafts. The clutch units include friction elements that
are axially compressed against friction elements that are
ultimately rotationally fixed to the crankshaft. A dual clutch
actuation device generates the apply force necessary to axially
compress the friction elements and rotationally couple the input
shafts with the crankshaft.
While current dual clutch actuation devices achieve their intended
purpose, the need for new and improved configurations which exhibit
improved performance, is essentially constant. For example, one
problem not addressed by the prior art is the contamination of the
actuation device by particles generated by the wearing of the
friction elements of the dual clutch. Accordingly, there is a need
in the art for a dual clutch actuation device having improved
packaging while providing a mechanism to reduce or eliminate
contamination of the actuation device.
SUMMARY
The present invention provides a dual clutch actuation device for a
dual clutch transmission. The transmission has two input shafts a
first shaft and a second shaft that is a hollow sleeve shaft. The
second shaft is concentric with the first shaft. A dual clutch
having two clutch units selectively couples a crankshaft of an
engine to one of the two input shafts. More specifically, the dual
clutch includes members such as a clutch housing having a first set
of frictional elements that are rotationally fixed to the
crankshaft through a flywheel and other members such hubs having a
second set of frictional elements that are rotationally fixed to
the input shafts. The first and second frictional elements are
axially compressed against each other to couple one of the hubs to
the dual clutch housing, thereby transmitting torque from the
crankshaft to one of the input shafts. A dual clutch actuation
device is provided to generate the axial compression force required
to compress the first and second set of frictional elements. Dual
clutch actuation device includes a first and second annular piston.
The annular pistons include a first end that is in contact with
annular bearing assemblies. The annular bearing assemblies are in
contact with actuation levers that are in contact with the first
set of frictional elements. The annular pistons are arranged in
concentric annular piston slots. Together the piston and annular
slots form annular piston chambers. The piston chambers are filled
with hydraulic fluid. When the hydraulic fluid is pressurized the
pistons slide out of the annular slots and apply a force on the
actuation levers which in turn apply an axial compression force on
the frictional elements.
In one aspect of the present invention, the dual clutch actuation
device includes a first and second annular channel in each of the
annular pistons.
In another aspect of the present invention, the dual clutch
actuation device includes a first set of wiper seals and a second
set of wiper seals disposed in the first and second annular
channels in each of the annular pistons.
In another aspect of the present invention, the dual clutch
actuation device includes a housing having a first annular slot
that is radially inward of a second annular slot.
In yet another aspect of the present invention, the dual clutch
actuation device includes a housing having a central bore
concentric with the annular slots and inward of the first annular
slot.
In yet another aspect of the present invention, the dual clutch
actuation device includes a position sensor attached to the housing
of the actuation device.
In yet another aspect of the present invention, a position sensor
includes two sensing elements, one for sensing the position of the
first annular piston and the other for sensing the position of the
second annular piston.
The above features and advantages and other features and advantages
of the present invention are readily apparent from the following
detailed description of the best modes for carrying out the
invention when taken in connection with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a partial cross-sectional view of a torque transmitting
device for a dual input transmission, in accordance with an
embodiment of the present invention;
FIG. 2A is a perspective view of front side of an actuation device
for activating the torque transmitting device of FIG. 1., in
accordance with an embodiment of the present invention;
FIG. 2B is a perspective view of back side an actuation device for
activating the torque transmitting device of FIG. 1., in accordance
with an embodiment of the present invention;
FIGS. 3A and 3B are partial cross-sectional views of the actuation
device of FIGS. 2A. and 2B. illustrating the position of seals on
the annular pistons, in accordance with an embodiment of the
present invention;
FIG. 4 is a front view of the actuation device of FIGS. 2A. and 2B.
attached to a wall of the housing of a transmission, in accordance
with an embodiment of the present invention; and
FIGS. 5 and 6 are perspective views of a sensor for sensing the
position of the actuation device shown in FIGS. 2A. and 2B., in
accordance with an embodiment of the present invention.
DESCRIPTION
Referring to FIG. 1, a partial cross-sectional view of a torque
transmitting device for a dual input transmission (not shown) is
generally indicated by reference number 10. The torque transmitting
device 10 is for example a dual clutch disposed in a vehicle
powertrain. Typically the vehicle powertrain includes an engine and
a transmission. In the instant embodiment the transmission includes
is a dual input transmission where torque is transferred from the
engine via a crankshaft 12 to two input shafts in the transmission:
a first input shaft 14 and a second input shaft 16 through
selective operation of torque transmitting device 10. The second
input shaft 16 is a sleeve (or hollow) shaft that is concentric
with and overlies the first input shaft 14. Torque transmitting
device 10 is disposed in a transmission housing or bell housing
18
Torque transmitting device 10 has two separate and independent
friction clutches 20 and 22 disposed in a clutch housing 24. Clutch
housing 24 is rotationally fixed to a flywheel 25. Flywheel 25 is
connected to crankshaft 12 and is preferably a dual mass flywheel
that is configured to dampen and reduce vibration in the crankshaft
12. Friction clutches 20 and 22 each include friction members 26
and 28. Friction members 26 and 28 are fixed to hub members 30 and
32, respectively. Hub members 30 and 32 are each rotationally fixed
to first and second input shafts 14 and 16, respectively. Clutch
housing 24 also includes a center plate 33 supported by a bearing
and friction elements 34 and 36 that are attached and rotationally
fixed to housing 24. Friction members 26 and 28 and friction
elements 34 and 36 are configured to form a friction clutch, as is
known in the art as a dual clutch. Thus, selective engagement
through axial compression of friction member 26 with friction
element 34 connects the crankshaft 12 for common rotation with the
first input shaft 14. Selective engagement of friction member 28
with friction element 36 connects the crankshaft 12 for common
rotation with the second input shaft 16. Friction clutches 20 and
22 may include multiple friction members 26 and 28 that interact
with a respective multiple of friction elements 34 and 36 connected
to housing 24. The number and size of the friction members will
vary based on appropriate torque transmission requirements. Of
course, the torque transmission capability of device 10 may be
varied by varying the number of friction elements and amount of
surface area of each friction element.
The coupling of the crankshaft 12 to the input shafts 14 and 16 is
achieved through axial compression of the friction elements by
actuation levers 38 and 40. Actuation levers 38, 40 have first end
42, 43 that is in contact with and configured to pivot on housing
24. The second ends 44, 45 are in contact with and configured to
receive an apply force generated by an actuation device 50.
Referring now to FIGS. 1 through 4, actuation device 50 includes an
annular housing 52, a pair of annular pistons 54 and 56 and a pair
of bearing assemblies 58 and 60. Housing 52 is mounted and thus
rotationally fixed to bell housing 18 and defines a central bore
61, a pair of annular slots 62 and 64. The central bore 61 is sized
to allow the first input shaft 14 and the second input shaft 16 to
pass there through. Annular slot 62 is concentric with and disposed
radially inward of annular slot 64. The annular pistons 54 and 56
are configured to slide axially within the slots and form piston
chambers 66 and 68 therewith. Annular pistons 54 and 56 further
include seals 70 and 72, respectively, fixed to an end of pistons
54 and 56. Seals 70 and 72 are configured to prevent excessive
leakage of hydraulic fluid between a wall of the piston chambers 66
and 68 and the ends of the pistons. Piston chambers 66 and 68 are
filled with hydraulic fluid through clutch feed bores 74 and 76.
Bearing assemblies 58 and 60 are actuation bearings that
torsionally decouple the rotating elements of clutch 10 (i.e.
housing 24 and actuation levers 38 and 40) from the non-rotating
members of the actuation device 50 (i.e. pistons 54 and 56).
With specific reference now to FIGS. 3A and 3B, the actuation
device 50 includes additional seals herein referred to as a first
set of wiper seals 78 and 79 and a second set of wiper seals 81 and
83. First set of wiper seals 78 and 79 are disposed in annular
channels 85 and 87, respectively. Second set of wiper seals 81 and
83 are disposed in annular channels 89 and 91, respectively.
Annular channels 85 and 87 are formed in annular piston 54 and
annular channels 89 and 91 are formed in annular piston 54. Annular
channel 85 has an open end that opposes a wall 95 of slot 62 of
housing 52. Annular channel 87 has an open end that opposes a wall
97 of slot 62 of housing 52. Similarly, annular channel 89 has an
open end that opposes a wall 99 of slot 64 of housing 52 and
annular channel 91 has an open end that opposes a wall 101 of slot
64 of housing 52.
First set of wiper seals 78 and 79 and second set of wiper seals 81
and 83 are configured to protrude from the respective annular
channels 85, 87, 89 and 91 to insure a constant seal with the walls
95, 97, 99 and 101. More specifically, each of the wiper seals 78,
78, 81 and 83 include a body portion 120 and a wiper portion 122.
The body portion 120 of wiper seal 78 is positioned substantially
within the annular channel 85 while the wiper portion 122 protrudes
from the channel 85 as required to contact and seal against wall
95. The body portion 120 of wiper seal 79 is positioned
substantially within the annular channel 87 while the wiper portion
122 protrudes from the channel 87 as required to contact and seal
against wall 97. The body portion 120 of wiper seal 81 is
positioned substantially within the annular channel 89 while the
wiper portion 122 protrudes from the channel 89 as required to
contact and seal against wall 99. The body portion 120 of wiper
seal 83 is positioned substantially within the annular channel 91
while the wiper portion 122 protrudes from the channel 91 as
required to contact and seal against wall 101.
In operation, first set of wiper seals 78 and 79 function to seal
and prevent the flow of hydraulic fluid and/or debris from entering
piston chamber 66. Accordingly, second set of wiper seals 81 and 83
function to seal and prevent the flow of hydraulic fluid and/or
debris from entering piston chamber 68. Typically, the friction
materials in the clutch 10 will break down over time and produce
free floating particles throughout the bell housing 18. The present
invention, advantageously, substantially eliminates the
contamination, caused by free floating particles in the bell
housing 18, of piston chambers 66 and 68 of actuation device 10.
The contamination is reduced or eliminated through the wiping or
cleansing action of the first set of wiper seals 78 and 79 against
walls 95 and 97 and the second set of wiper seals 81 and 83 against
walls 99 and 101.
With continuing reference to FIGS. 2A, 2B and now referring to
FIGS. 5 and 6, position sensor 80 is fixed to housing 52 for
sensing the movement and location of annular pistons 54 and 56.
Position sensor 80 includes a sensor housing 82 having a pair of
apertures 90 formed therein. Housing 52 includes mounting pins 92
attached to a side of housing 52 that cooperate with apertures 90
formed in sensor 80. The engagement of pins 92 with apertures 90
insures the required orientation and location of sensor 80 relative
to annular pistons 54 and 56. More specifically, position sensor 80
includes first and second sensing elements 94 and 96. First and
second sensing elements 94 and 96 extend perpendicular to a base
100 of sensor housing 82. First sensing element 94 is disposed
between annular pistons 54 and 56 and is configured to sense the
movement and position of piston 54. Second sensing element 96 is
disposed radially outside of annular pistons 54 and 56 and is
configured to sense the movement and position of piston 56. Second
sensing element 96 is threaded through an annular ring 102 in a
bracket 104 that is fixed to piston 56. The axial movement of ring
102 along sensing element 96 alters the electrical properties of
sensor element 96 and generates signal in sensor 80 indicative of a
position of piston 58. Sensor 80 is any suitable sensor including
Hall Effect sensors, variable reluctance sensors and the like.
In operation hydraulic fluid is pressured and forced through clutch
feed bores 74 and 76 to push pistons 54 and 56 out of their
respective piston chambers 66 and 68 towards clutch 10. More
specifically, pressurized hydraulic fluid is pushed through clutch
feed bore 74 into piston chamber 66 forcing annular piston 56 to
slide out of the chamber towards clutch 10. As annular piston 56
moves out of the chamber bearing assembly 58 which is in contact
with annular piston 56 applies a force to one end of the actuation
lever 40. Actuation lever 40 in turn compresses friction element 34
axially against friction member 26 causing friction member 26 to
rotate at substantially the same speed as friction element 34.
Thus, selectively rotationally coupling crankshaft 12 with first
input shaft 14. Similarly, pressurized hydraulic fluid is pushed
through clutch feed bores 76 into chamber 68 forcing annular piston
54 to slide out of the chamber towards clutch 10. As annular piston
54 moves out of the chamber bearing assembly 60 which is in contact
with annular piston 54 applies a force to one end of the actuation
lever 38. Actuation lever 38 in turn compresses friction element 36
axially against friction member 28 causing friction member 28 to
rotate at substantially the same speed as friction element 36.
Thus, selectively rotationally coupling crankshaft 12 with second
input shaft 16.
While the best modes for carrying out the invention have been
described in detail, those familiar with the art to which this
invention relates will recognize various alternative designs and
embodiments for practicing the invention within the scope of the
appended claims.
* * * * *